Renters: Beware of new twists on an old scam (© Jupiterimages; Steve Taylor/Getty Images)

The scam is as old as desire itself: sell a "super" product at a "low price," then make off with the cash as the victim discovers he's been left with a fake bill of goods.

Now, with a slow economy and more Americans in need of affordable housing, the age-old ploy is rife in the rental market. The rental scam comes in several variations, but it typically follows the same basic recipe: A con artist finds a property, pretends to be the owner, lists it online, then communicates with the would-be renter and takes a cash deposit.

The renter is left with nothing or ends up squatting on someone else's vacant property while paying "rent" to a fraudster, all unbeknownst to the property's real owner.

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Familiarizing yourself with the scam can help you avoid being one of its unwitting victims. With that in mind, here's a quick rundown of its various forms, followed by a list of tips on how to avoid falling prey to even the cleverest trickster.

A pretend owner ‘rents’ out a vacant home
Even criminals are subject to market conditions. If thousands of abandoned homes sit empty and thousands of people are in need of cheap housing, someone is eventually going to put the two together, legal or not.

In this case, the scam artist steps in to take advantage of the situation.

He finds an abandoned property, or two or three (these days, it's not hard), and creates an online advertisement pretending to be either the owner or someone authorized to rent on the owner's behalf.

He then breaks in, sometimes changing the locks, and typically asks to be paid in cash. In Las Vegas, a woman arrested for just such a scam had provided a contract and written rental receipts to a mother of two, and instructed the woman to meet her each month in a public location to pay her cash "rent," according to a story in the Las Vegas Sun.

The real owner, who lived in California, arrived one day to find a family living in the home.

"When a house sits vacant for a year it becomes easier to take advantage of it. Six months of collecting rent at $1,500 can be hard to pass up," said Sean O'Toole, founder and CEO of ForeclosureRadar.com, which tracks foreclosures in California.

As proof, take a case this year in Fremont, Calif., in which a former licensed Realtor rented out foreclosed homes at least 13 times before he was caught by a visiting owner. Police said he had 19 more foreclosed homes lined up to rent and had identified 126 others. He copied listings from the Multiple Listing Service and somehow obtained the key codes. He then instructed the would-be renters to change the locks, according to news reports.

Tenants in such cases did not intend to occupy a house illegally and aren't going to be charged with a crime, police say. But the renters are going to have to move on short notice and are unlikely to see their security deposits again.

A fake agent pretends to rent a foreclosed property then splits before the renter moves in
This scam starts in much the same way, except the con artist supplies a throwaway or fake phone number and never supplies the keys to the property. He may also collect a deposit from several victims at a time.

In this case, the victim is out both the money and a place to live.

In Miami recently, a con artist went so far as to create a fake warranty deed and introduce himself to neighbors as the new owner.

"He showed me the house. He had a key. He knew the floor plans of the house, everything about the house. It was convincing," the alleged victim, a teacher who handed over a $3,000 deposit, told the Local 10 television news.

As it turned out, several others had handed over deposits, too, and had shown up with moving trucks only to find they were unable to get in.

"It's very, very devastating," the teacher told reporters.

A fake property manager pretends to rent out a home that's for sale
In this case, the con artist hijacks listings of homes that are for sale or rent by legitimate agencies. He may rewrite the ad a bit before posting it online (often on Craigslist, where posts are free), including undercutting the original price by as much as half.

When interested tenants respond, eager to secure such a good deal, the con artist may claim to need a cash deposit or application information – containing personal data that can be mined for identity theft – before arrangements can be made to view the apartment. The scammer may say he is out of state for work, or for some other reason has to rush to rent the apartment from afar.

The con artist may also use the name of an actual leasing agent and agency; when renters go online, they believe they are verifying the self-proclaimed agent's identity. (See more on how to protect yourself.)

One woman in Florida who got access to a real-estate agent’s lock-box codes, apparently by pretending to be agent, printed rental contracts and business cards, which she displayed inside the home after hiding the real agent's cards in a drawer, police said.

She also pulled the true realty sign from the yard and hid it in the garage during home tours. When one couple spotted the sign, she told them to ignore the telephone number on it, a move that made the couple suspicious and ultimately led to a police sting.

"If you were to listen to her when she was actually doing any transactions you wouldn't think twice about it," said Chuck Lee, an investigator with the Volusia County Sheriff's Office in Florida, who followed one of her presentations. "She was very smooth."

The woman would fill out a rental agreement on the spot and take a cash deposit, making arrangements to deliver the keys later and providing a telephone number, police said. She received money for several homes before she was arrested and charged, police said.

A real owner rents his foreclosed property
At times the scam artist is a desperate homeowner. Authorities say owners approaching, or in, foreclosure have been renting the property and pocketing the cash, removing eviction signs from the property to keep tenants in the dark as long as possible.

Renters may not learn their money has been taken until eviction day, although government agencies have been working to ensure that tenants get at least three months to move after a confirmed notification.

When renting, "you should as a matter of course check whether the property is in foreclosure or not," said ForeclosureRadar.com's O'Toole.

One free site dedicated to helping renters with this task is RentalForeclosure.com, where you can type in the property's address.

A con artist borrows a real apartment or address and collects deposits and Social Security numbers
Instead of borrowing a listing, the scammer creates his own for an occupied apartment that he has borrowed or even temporarily rented using phony identification. He advertises a low price and creates a sense of urgency to encourage people to hand over cash and an application containing Social Security numbers to hold the unit.

For a dramatized example of how such a ruse is carried out— and how easy it is to fall for — check out this video by "The Real Hustle."

In the end, the victim risks losing not just cash but his identity and banking information.

A con artist rents a real, but unavailable, apartment to tourists  
Anyone can list a property as a vacation or temporary rental, and it attracts those visiting or moving from out of town. But a scammer will request that a security deposit and rent money be wired in advance, as opposed to accepting a credit card or check.

Visitors show up at the address to find no apartment and no valid contact information. Authorities say it is almost impossible to recover money that has been wired, which is almost as untraceable as cash, or even to find the perpetrators.